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Soichiro Kitamura

Publications and source records attributed to Soichiro Kitamura.

At least 37 records · Page 2Linked to original sources
PubMed2006

Biventricular repair for right atrial isomerism.

BACKGROUND: Biventricular repair is often difficult to accomplish in patients with right atrial isomerism because of complex anomalous structures. METHODS: Ten patients with right atrial isomerism underwent biventricular repair. Their ages ranged from 15 months to 21 years. The follow-up period ranged from 1 month to 21 years. The Fontan procedure was unsuitable in 7 patients. The atrioventricular valves were separated in 5 patients and common in 5. One patient who had severe right-sided atrioventricular valvular regurgitation required concomitant prosthetic valve replacement. Another patient with a hypoplastic intraventricular septum underwent ventricular septation. Nine patients had two balanced ventricles. A ventricular septal defect was enlarged for rerouting in 3 patients. All patients had anomalous venoatrial connections and required intra-atrial baffle rerouting. One with major aortopulmonary collateral arteries underwent staged unifocalization. Three had extracardiac conduit repair. The outcomes were compared with 97 patients who underwent the Fontan procedure. RESULTS: There were 3 early deaths and 1 late death. Six survivors are in New York Heart Association functional class I or II. Two are free from medications. Two required reoperation owing to infection or prosthetic valve failure. At 1 year, cardiac index and systemic venous pressure were 3.2 +/- 0.9 L.min(-1).m(-2) and 6.6 +/- 1.6 mm Hg, respectively. There were no significant differences in survival, freedom from arrhythmia, freedom from reoperation, or exercise tolerance between biventricular repair and the Fontan procedure. CONCLUSIONS: Biventricular repair provided good long-term outcomes in patients with right atrial isomerism. In selected circumstances, biventricular repair is an acceptable alternative to the Fontan procedure.

Abnormalities, Multiple↗
PubMed2006

Limitations of EuroSCORE for measurement of risk-stratified mortality in aortic arch surgery using selective cerebral perfusion: is advanced age no longer a risk?

BACKGROUND: The European system for cardiac operative risk evaluation (EuroSCORE) is a risk stratification tool for perioperative mortality of cardiothoracic surgery that was developed in Europe and validated in North America in more than 500,000 patients. The operative mortality of aortic arch surgery has been improved by various novel operative techniques and adjuncts, whereas the number of such procedures for elderly patients has recently been increasing. The aim of this study was to examine the usefulness of the EuroSCORE, and our modification of it regarding age, in predicting mortality after aortic arch repair performed with selective cerebral perfusion. METHODS: We reviewed 358 consecutive patients with a mean age of 69 +/- 10 years undergoing aortic arch repair with selective cerebral perfusion between January 1993 and February 2004. Observed in-hospital mortality was compared with predicted mortality as determined by both additive and logistic EuroSCOREs. We also evaluated a version of the EuroSCORE modified for age, which was obtained by subtracting the contribution of age from the original EuroSCORE. Score validities were assessed by calculating the areas under receiver operating characteristic curves. RESULTS: Overall hospital mortality was 6.2% compared with 7.7% (additive EuroSCORE) and 11.8% (logistic EuroSCORE). Area under the receiver operating characteristic curve was 0.58 for the additive EuroSCORE and 0.58 for the logistic EuroSCORE as well. The overall age-unrelated EuroSCOREs were 5.1% (additive) and 5.2% (logistic), respectively, and areas under the receiver operating characteristic curve were 0.70 for additive and 0.69 for logistic. CONCLUSIONS: The original additive and logistic EuroSCOREs overpredicted mortality in this patient group, whereas the age-unrelated EuroSCORE was better in predicting mortality.

Age Factors↗
PubMed2006

Partial anomalous pulmonary venous connection to the superior vena cava.

BACKGROUND: Repair of partial anomalous pulmonary venous connection (PAPVC) to the high portion of the superior vena cava (SVC) may be complicated by atrial arrhythmia and obstruction of the pulmonary veins or SVC. We reviewed our experience with the modified Warden technique, in which the SVC was transected and anastomosed to the right atrial appendage with anterior augmentation of pedicled autologous pericardial flap, and the atrial septum was directly displaced to the SVC orifice. METHODS: Twenty of 51 patients with PAPVC underwent this technique. Mean age was 11.9 years. Follow-up averaged 6.5 years. To quantify the height of insertion of anomalous pulmonary veins, the distance between the highest anomalous pulmonary venous orifice and SVC-right atrial junction was indexed by thoracic vertebral body height (height index). RESULTS: All patients are alive in sinus rhythm. No patients exhibited pulmonary venous obstruction, and mean flow was 0.61 mL. Mean flow of SVC return was 0.79 mL. The SVC occlusion occurred in 2 patients who had persistent left SVC with a good communicating vein. Three patients whose height index exceeded 2.5 successfully underwent catheter intervention at the SVC channel. CONCLUSIONS: Midterm results with the modified Warden technique were satisfactory. Patients with particularly high insertion of anomalous pulmonary veins should be treated and followed with specific caution for preserving an unobstructed caval pathway.

Adolescent↗
PubMed2006

Combined use of adamkiewicz artery demonstration and motor-evoked potentials in descending and thoracoabdominal repair.

BACKGROUND: We retrospectively reviewed the outcome of distal descending aortic and thoracoabdominal aortic repair with preoperative identification of the Adamkiewicz artery by magnetic resonance angiography and intraoperative monitoring of transcranial motor-evoked potentials. METHODS: We began combined use of demonstration of the Adamkiewicz artery and intraoperative recording of motor-evoked potentials for prevention of spinal cord complications in descending and thoracoabdominal aortic aneurysm repair in 1998. Ninety-two consecutive patients were studied, with descending aneurysm in 53 and thoracoabdominal aneurysm in 39 patients. The repair was performed through a left thoracic or thoracoabdominal incision, using partial cardiopulmonary bypass to prevent spinal cord injury. Magnetic resonance angiography revealed the Adamkiewicz artery in 70.7% of cases. During surgery, spinal cord ischemia was monitored using motor-evoked potentials. Anastomoses were performed using a segmental clamp technique to reduce spinal cord ischemic time. Based on the findings of magnetic resonance angiography and motor-evoked potentials, the Adamkiewicz artery and other relevant intercostals and lumbar arteries were revascularized or preserved, or both. RESULTS: The mean durations of partial cardiopulmonary bypass, cross-clamping, and surgery, respectively, were 144.4 +/- 232.2, 106.0 +/- 65.5, and 411.8 +/- 170.7 minutes. Three hospital deaths (3.3%) occurred in patients with a thoracoabdominal aortic aneurysm. Motor-evoked potentials changed in 9 patients (9.8%), in 8 (88.9%) of whom they were eventually restored. Although paraplegia developed in 1 patient (1.1%) with a mycotic descending aneurysm, the other patients survived without spinal cord injury. CONCLUSIONS: Combined visualization of the Adamkiewicz artery and determination of motor-evoked potentials are useful in preventing spinal cord injury in descending and thoracoabdominal aortic repair.

Adult↗
PubMed2006

Long-term recovery of exercise ability after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension.

BACKGROUND: The exercise capacity of patients with thromboembolic pulmonary hypertension was investigated to clarify the long-term effects of pulmonary endarterectomy. This capacity was assessed by measuring cardiopulmonary factors during cardiopulmonary exercise testing at the maximal level of exercise and a 6-minute walk test at the submaximal level. Their survival rate was also determined. METHODS: We conducted a retrospective review of the clinical records of 102 patients who underwent pulmonary endarterectomy (63 women; median age, 53 years). RESULTS: Eight (7.8%) hospital mortalities were encountered. Three late mortalities due to fulminant hepatitis, breast cancer, and pneumonia in a patient under steroid therapy were unrelated to pulmonary endarterectomy. The actual survival rate including hospital mortalities was 90.9% at 3 years and 84.0% at 5 years. All hemodynamic measurements significantly improved and reached a plateau 1-month after endarterectomy. The cardiopulmonary exercise test at the maximal exercise level revealed that peak oxygen uptake (V(O2)) baseline was 13.8 +/- 3.2 mL/min/kg, and at 1-month was 16.2 +/- 4.2 mL/min/kg (p = 0.0015) and ventilatory response to carbon dioxide production (V(E)-V(CO2)) slope baseline was 46.5 +/- 8.4 mL/min/kg, and at 1-month was 39.9 +/- 7.4 (p = 0.0006), which gradually and significantly improved during the first year after endarterectomy (peak V(O2), 19.9 +/- 3.9 mL/min/kg [p < 0.0001] and V(E)-V(CO2) slope, 33.2 +/- 5.4 mL/min/kg [p <0.0001]). The 6-minute walk test, which reflects the systemic response at the submaximal level of functional capacity, showed that the walking distance gradually and significantly increased for up to 1 year after endarterectomy (baseline, 358 +/- 102 meters [m]; at 1-month, 433 +/- 105 m; and at 1-year, 490 +/- 80 m [p < 0.0001]) and then reached a plateau. CONCLUSIONS: After pulmonary endarterectomy, the hemodynamic recovery occurred immediately, and the patients' exercise capacity improved during the year. The 6-minute walk test was a good indicator to assess the recovery of exercise capacity.

Adult↗
PubMed2006

Japanese single-center experience of surgery for chronic thromboembolic pulmonary hypertension.

BACKGROUND: We review the outcome of surgery for chronic thromboembolic pulmonary hypertension (CTEPH). METHODS: Between 1995 and 2004, 88 patients underwent surgery for CTEPH. Mean pulmonary artery pressure and pulmonary vascular resistance were 46 mm Hg (range, 23 to 70 mm Hg) and 986 dynes.sec(-1).cm(-5) (298 to 2,231 dynes.sec(-1).cm(-5)). The pulmonary artery lesion was proximally located in 51 patients, subsegmental in 34 patients, and peripheral in 3 patients. Pulmonary endarterectomy was performed using cycles of 15-minute intermittent circulatory arrest followed by 10-minute reperfusion at 16 degrees C to 18 degrees C. RESULTS: The median durations of circulatory arrest, cardiopulmonary bypass, and surgery were 58, 217, and 355 minutes, respectively. Percutaneous extracorporeal membrane oxygenation was used in 8 patients (9.1%) who had difficulty being weaning from cardiopulmonary bypass. Three recent patients for whom this was performed promptly were weaned and survived. There were 7 hospital deaths (8.0%, including 6 30-day deaths) from pulmonary bleeding in 2 patients, residual pulmonary hypertension in 3, rupture of bulla in 1, and empyema in 1. In the 81 survivors, mean pulmonary artery pressure and pulmonary vascular resistance fell significantly after surgery (p < 0.0001, each case). Age more than 60 years was a risk factor for hospital mortality on multivariate analysis. Although distal pulmonary artery disease including subsegmental and peripheral lesions was not a significant risk factor for mortality, it did influence patient recovery: the frequency of percutaneous extracorporeal membrane oxygenation was higher and hemodynamic improvement less pronounced in patients with distal disease. The actuarial survival rate was 90.7% at 3 years and 86.4% at 5 years. None of the patients have suffered recurrence. The event-free rate was 97.1% at 3 years and 93.5% at 5 years. Of the 68 patients surviving for more than 1 year after surgery, 67.6% were successfully weaned from home oxygen therapy and 13.2% required only occasional use of oxygen. CONCLUSIONS: Pulmonary endarterectomy can be safely performed with relatively low mortality and favorable prognosis with long-term survival, although it should be performed carefully for patients with distal disease.

Adult↗
PubMed2006

Angiographic flow grading and graft arrangement of arterial conduits.

OBJECTIVE: We sought to delineate the effects of competitive and reverse flow on the intermediate-term patency of arterial conduits and examined graft arrangements for maximizing antegrade bypass flow. METHODS: The angiograms of 2083 bypass grafts in 570 patients who underwent off-pump total arterial revascularization without aortic manipulation since December 2000 were reviewed. The blood flow in the bypass grafts were graded A (antegrade), B (competitive), C (reverse), or O (occlusion). The mean number of distal anastomoses was 3.65 +/- 0.94 per patient. RESULTS: In the early angiography 91.3% (1901/2083) of the bypasses were grade A. Thirty (1.4%) bypasses were grade O, whereas 2.9% (61/2083) were grade B, and 4.4%(91/2083) were grade C. In the multivariate analysis the end-to-side anastomosis (P < .0001), 4 or more distal anastomoses of the conduit (P = .01), native coronary stenosis of less than 75% (P < .0001), and target branch location of the right coronary artery territory (P < .0001) and left circumflex artery territory (P = .02) significantly correlated with grade non-A. The patency rate in the late angiography of the bypasses graded B or C in the early angiography was 7 (28.0%) of 25, whereas that of the bypasses graded A was 164 (89.1%) of 184 (P < .0001). The actuarial graft patency rate of the bypasses graded A was 72.3% at 3 years and was significantly higher than that of the bypasses graded B or C (28.6% at 3 years after surgical intervention, P < .0001). CONCLUSIONS: The sufficient antegrade bypass flow had a favorable effect on the graft patency of arterial conduits. The graft arrangement should be adjusted for each patient so as to maximize the antegrade bypass flow and to confirm the advantage of arterial grafts.

Aged↗
PubMed2006

Valve repair with maze procedure in acromegaly.

Acromegaly is characterized by a hypersecretion of growth hormone and is frequently associated with valvular abnormality and arrhythmia. The increased morbidity and mortality is primarily caused by stroke and cardiovascular disease. Therefore, valve reconstruction and sinus rhythm recovery will be particularly beneficial. We report herein the successful surgical treatment of two patients with combined valvular insufficiency and chronic atrial fibrillation in the setting of acromegaly.

Acromegaly↗
PubMed2006

Off-pump coronary artery bypass grafting for acute myocardial infarction.

BACKGROUND: The aim of this study was to evaluate the surgical results of off-pump coronary artery bypass grafting (OPCAB) for patients with acute myocardial infarction (AMI) within 14 days of the infarction. METHODS AND RESULTS: From April 2000 to January 2005 among 841 patients who underwent OPCAB, 43 consecutive patients (5.1%) were examined. Mean age at operation was 69.5 years and mean time from the onset of AMI to surgery was 4.6 days. Seventeen patients (39.5%) had left main trunk disease. Three patients (7.0%) underwent OPCAB following unsuccessful percutaneous coronary intervention, and 1 patient (2.3%) underwent redo procedure 9 years after previous coronary artery bypass grafting (CABG). Six patients (14%) were admitted in cardiogenic shock. Intraaortic balloon pumping was inserted preoperatively in 20 patients (46.5%). The average maximum creatine kinase-myocardial band was 139+/-181 (U/L). The mean number of grafts was 3.2 and the rate of complete revascularization was 91%. Two of six patients with preoperative cardiogenic shock were converted to on-pump beating CABG due to ventricular arrythmia. The early graft patency rate was 98%. All patients survived except 2 with preoperative cardiogenic shock. CONCLUSIONS: OPCAB can be performed after AMI as a relatively low-risk procedure with an acceptable mortality rate, even within 14 days of the infarction.

Aged↗
PubMed2006

Monoparesis after graft replacement of non-ruptured abdominal aortic aneurysm.

A 67-year-old man was admitted with a saccular aneurysm of the abdominal aorta. Preoperative CT revealed cylindrical calcification of the abdominal aorta and the patent internal iliac arteries (IIAs). At the elective surgery, a cylinder-shaped and severely calcified intimal layer was found, and the lumbar arteries were totally occluded. Hypotension caused by the loose iliac clamp due to severe calcification continued for 15 minutes and long-time cross clamp was necessary. Monoparesis of the left lower extremity and dysuria occurred postoperatively. Spinal MRI revealed small infarction at the Th10 level. Symptoms improved and he could walk with a cane and within a few months no uninary catheter support was needed. Thoracic spinal cord infarction after abdominal aortic aneurysm (AAA) surgery and a severely calcified abdominal aorta indicated the importance of the blood flow in the IIA as the significant source of spinal blood supply. To prevent spinal cord injury (SCI) which is rare but significant complication of AAA surgery, understanding of the spinal blood supply, quick surgery, and complete revascularization of pelvic arteries are important.

Aged↗
PubMed2005

Surgical treatment of aortic regurgitation due to Takayasu arteritis: long-term morbidity and mortality.

BACKGROUND: The goal of this retrospective study was to determine the late outcome of surgical treatment for aortic valve regurgitation due to Takayasu arteritis and correlate it with evidence of inflammation on pathological examination. METHODS AND RESULTS: Ninety consecutive patients who underwent surgery for aortic valve regurgitation due to Takayasu arteritis between 1979 and 2003 were studied. Intraoperative pathological specimens of the aortic wall from 69 patients were retrospectively examined for inflammation. Aortic valve replacement was performed in 63 patients (group A) and composite graft repair in 27 patients (group B). The aortic root diameter was 39.9+/-9.5 mm in group A and 54.4+/-13.6 mm in group B (P<0.0001). Preoperative steroid therapy was performed in 40 patients (44.4%). Hospital mortality was 4.8% (3/63) in group A and 7.4% (2/27) in group B. The overall 15-year survival rate was 76.1%. Detachment of the valve or graft occurred in 11.1% (7/63) of group A and in 3.7% (1/27) of group B patients (P=0.43). Late dilatation (>50 mm) of the residual ascending aorta occurred in 11.1% (7/63) of group A and in 3.7% (1/27) of group B patients (P=0.43). Active inflammation was confirmed in intraoperative pathological specimens of 10 patients, and detachment of the valve or graft occurred in 4 of these patients. Univariate analysis of background variables revealed active inflammation to be a risk factor for detachment (P=0.0001; risk ratio 55). CONCLUSIONS: Late dilatation of the ascending aorta after aortic valve replacement is a clinically important finding. Active inflammation could be related to valve or graft detachment.

Adult↗
PubMed2005

Early outcome of a randomized comparison of off-pump and on-pump multiple arterial coronary revascularization.

BACKGROUND: Previous randomized comparisons of off-pump and on-pump coronary artery bypass grafting (CABG) have yielded controversial results about the cardiac and neurological events and graft patency. In addition, these randomized studies were composed of CABG with a few arterial grafts. We performed a prospective randomized controlled study to compare off-pump and on-pump CABG with multiple arterial grafts. METHODS AND RESULTS: Between July, 2002, and September, 2004, 167 consecutive unselected patients referred for elective primary CABG were randomly assigned to undergo multiple arterial off-pump CABG (n=81) or on-pump CABG (n=86). The clinical outcomes and S-100 protein, neuron-specific enolase, and maximum creatine kinase-MB levels were compared. Early graft patency was examined within 3 weeks after the operation by angiography. The number of grafts performed per patient (3.5+/-1.0 for off-pump CABG and 3.6+/-0.9 for on-pump CABG) and the number of arterial grafts performed per patient (3.3+/-1.0 for off-pump CABG and 3.4+/-0.9 for on-pump CABG) were similar. Completeness of revascularization (completed grafts/planned grafts) was 98% in both procedures. There were no hospital deaths in either group. The operation time was significantly (P<0.001) shorter in the off-pump group than in the on-pump group (267+/-60 minutes versus 307+/-59 minutes). The incidence of perioperative complications was similar. The frequency of no need for transfusion was higher in the off-pump group than in the on-pump group (80% versus 55%, P<0.001). The S-100 protein levels at the admission into the intensive care unit were significantly (P<0.001) lower in the off-pump group than in the on-pump group (0.20+/-0.11 ng/mL versus 0.34+/-0.22 ng/mL). The neuron-specific enolase levels at the intensive care unit admission were significantly (P<0.001) lower in the off-pump group than in the on-pump group (10.4+/-9.0 ng/mL versus 16.9+/-6.9 ng/mL). Maximum creatine kinase-MB levels were significantly (P=0.046) lower in the off-pump group than in the on-pump group (17.1+/-16.7 IU/L versus 21.5+/-10.6 IU/L). The overall early graft patency rate with or without stenosis was the same (98%) in both groups, but the rate without stenosis was slightly worse in the off-pump group (93%) than in the on-pump group (96%) (P=0.093). The stenosis-free patency rate in the right coronary area was significantly (P=0.028) worse in the off-pump CABG group (90%) than in the on-pump group (99%). CONCLUSIONS: Off-pump CABG with multiple arterial grafts was as safe as the conventional on-pump CABG, with similar completeness of revascularization and early graft patency.

Aged↗
PubMed2005

Transplantation of mesenchymal stem cells improves cardiac function in a rat model of dilated cardiomyopathy.

BACKGROUND: Pluripotent mesenchymal stem cells (MSCs) differentiate into a variety of cells, including cardiomyocytes and vascular endothelial cells. However, little information is available about the therapeutic potency of MSC transplantation in cases of dilated cardiomyopathy (DCM), an important cause of heart failure. METHODS AND RESULTS: We investigated whether transplanted MSCs induce myogenesis and angiogenesis and improve cardiac function in a rat model of DCM. MSCs were isolated from bone marrow aspirates of isogenic adult rats and expanded ex vivo. Cultured MSCs secreted large amounts of the angiogenic, antiapoptotic, and mitogenic factors vascular endothelial growth factor, hepatocyte growth factor, adrenomedullin, and insulin-like growth factor-1. Five weeks after immunization, MSCs or vehicle was injected into the myocardium. Some engrafted MSCs were positive for the cardiac markers desmin, cardiac troponin T, and connexin-43, whereas others formed vascular structures and were positive for von Willebrand factor or smooth muscle actin. Compared with vehicle injection, MSC transplantation significantly increased capillary density and decreased the collagen volume fraction in the myocardium, resulting in decreased left ventricular end-diastolic pressure (11+/-1 versus 16+/-1 mm Hg, P<0.05) and increased left ventricular maximum dP/dt (6767+/-323 versus 5138+/-280 mm Hg/s, P<0.05). CONCLUSIONS: MSC transplantation improved cardiac function in a rat model of DCM, possibly through induction of myogenesis and angiogenesis, as well as by inhibition of myocardial fibrosis. The beneficial effects of MSCs might be mediated not only by their differentiation into cardiomyocytes and vascular cells but also by their ability to supply large amounts of angiogenic, antiapoptotic, and mitogenic factors.

Animals↗
PubMed2005

Comparison of angiogenic potency between mesenchymal stem cells and mononuclear cells in a rat model of hindlimb ischemia.

OBJECTIVE: Mesenchymal stem cells (MSC) are pluripotent cells that differentiate into a variety of cells including endothelial cells and vascular smooth muscle cells. Although transplantation of bone marrow-derived mononuclear cells (MNC) has already been applied for the treatment of critical limb ischemia, little information is available regarding comparison of the angiogenic potency between MSC and MNC. Accordingly, we injected equal numbers of MSC or MNC in a rat model of hindlimb ischemia and compared their therapeutic potential. METHODS AND RESULTS: Immediately after creating hindlimb ischemia, rats were randomized to receive MSC transplantation (MSC group), MNC transplantation (MNC group), or vehicle infusion (Control group). Three weeks after transplantation, the laser Doppler perfusion index was significantly higher in the MNC group than in the Control group (0.69+/-0.1 vs. 0.57+/-0.06, P<0.01). Furthermore, there was a marked improvement in blood perfusion in the MSC group (0.81+/-0.08). Capillary density was highest in the MSC group. The number of transplanted cell-derived endothelial cells was higher in the MSC group than in the MNC group. Transplanted cell-derived vascular smooth muscle cells were detected only in the MSC group. In vitro, MSC were more tolerant to apoptotic stimulus (serum starvation and hypoxia) than MNC. CONCLUSIONS: MSC transplantation caused significantly greater improvement in hindlimb ischemia than MNC transplantation. Compared with MNC, MSC survived well under an ischemic environment, and differentiated into not only endothelial cells but also vascular smooth muscle cells. Thus, MSC transplantation may be a new therapeutic strategy for the treatment of severe peripheral vascular disease.

Animals↗